Class a nd Ord e r . TETRANDRIA TETRAGYNIA.
[Natural Ord er . FLUVIALES. Flores monoici rarius dioici. Cat. proprie dibtüs; nuliis. Sem. tinicumj
Inversum sive appensum. Embr. antiti'opus (seu radicula ad punctum hilo seminis contrarium versa).—Richarcl
in Mus. d ’Hist. Nat. fasc. 5. ALISMACEÆ, Decand. NAIADES, Jussieu.']
Gen. Ch a r. Flores hermaphroditi distichi in spadice soli tari o. Perianthium nullum; Stamina quatuor.
Ovaria quatuor. Capsula monospermæ, ovatæ, longfe pedicellâtæ;
Radix parva, fibrosa, fibris simplicibus, e geniculis cau-
liiim.
CaULIS pedalis, bipedalis et ultra, sed penna passerina
vix crassiof, geniculatus, flexuosus, teres, fusco-
' vjridis, valde ramosus, ramis saspe dichotomis,
ubique, a t ramorum divisione prascipue, foliosus.
Folia tri- quadri-uncialia, flexuosa, graminea,obtusa, vix
semilineam lata, nigro-viridia, glabra, superiora
natantia, basi vaginantia, vaginis subunciam lon-
gis, infiatis, membranaceis, fuscis.
Spadix (Jig. 3.) primum brevis, demum valde elonga-
tus, et more Vallisneria spiralis spiraliter tortus,
ex axilla foliorum spathaj vicem gerente, teres,
biflorus, floribus disticho modo dispositis; nempe
uno (superno) anteriore facie; altero (inferno)
posteriore facie (Jig. 3, 4).
Calyx nullus.
Corolla nulla.
Anther® (Jig. 3, 4, 5, Sc 6.) qüatüor, circa ovaria
positse, sessiles, subquadratte, magis latte quam
longffi,atque spadicem arete amplectentes,virides,
honzontaliter dehiscentes. Pollen minutum, pal-
lide viride, oblongo-cylindraceum, geniculatum,
geniculo apicibusque inflatum (Jig. 7 ).
Ovaria quatuor; e centro antherarum, parva, sessilia,
tuberculiformia (Jig. 3, 4. a.), demum pedicel-
lata, ovata, viridia (Jig. 1 1 ). Stylus nullus: Stigma
obtusum.
Pericarpia tot quot ovaria, longe pedicellata, dru-
pacea, nigro-viridia, late ovata, apice attenuata
(fig. 12). Cortex camoso-membranacea, puta-
men (Jig. 13,14,15, & 16.) crustaceum, evalve,
• nigrescens, punctis duobus utrinque sub apicem
notata (Jig. 15), dorso areola oblonga quasi
operculata (Jig. l 6),
SeMen (fig. 17, 18.) pendens (inversum, Rich J ova-
. turn, gibbosum, albicans.
Integumentum membranaceum.
Embryo semini conformis (fig. 19.), albus, sub lente
longitudinaliter elevato-punctatus.
Cotyledon ? (radicula Rich, vitellus Gcertn. (fig. 19,
2 0 . a. a.) magna, ovata, carnosa, solida, ad apicem
oblique truncata atque pro plumulte recep-
done canaliculata.
Plumula? (cotyledon Rich.) subulato-cylindracea
(fig- 19, 20. b. b.), oblique posita et ad hilum
seminis versa.
Radicula ? (fig. 2 0 . c.) basi plumules In tuberculo mi-
nuto.
(Root small, fibrous, the fibres simple, arising from the
joints'of the stem.
Stem from a foot to two feet long and, even more, but
scarcely thicker than a sparrow’s quill, jointed,
flexuose, round, brown-green, vdry much branched;
the branches often dichotomous, every where leafy,
but especially at the divisions of the branches.
Leaves three or four inches long; flekuose, grass-like,
obtuse, scarcely half a line wide, blackish green,
smooth, the superior ones floating, sheathing at
the base, with the sheaths about an inch long;
swelling out, membranaceous, broWn.
Spadix (fig. 3.) at first short, at length much lengthen^
ed out, and after the manner of Vallisneria spiralis
spirally twisted, arisiug from the axil o f the
leaves, which thus, perform die office o f a spathA;
round, two-flowered, the flowers placed in a distichous
manner; that is, one (the superior) on
the anterior side; the other (the lower one) on
the posterior side (fig. 3, 4)-.
Calyx none.4
Corolla none.
An thers (j £°\s-. 3 ,4 ,5 , and 6.) four, placed around the
ovaries, sessile, subquadrate, broader than they
are long, closely embracing the spadix, green, horizontally
opening. Pollen minute, pale green,
oblongo-cylindraceous, geniculate, at the bend
and the extremities inflated (fig. 7).
Ovaries fo u r; from the centre of the anthers, small,
sessile, resembling tubercles (figs. 3, 4. «.), at
length pedicellate, ovate, green (fig. ] I). Style
none; Stigma obtuse.
Pericarps as many as ovaries, on long footstalks,
drupaceous, blackish green, broadly ovate, attenuate
at the extremity (fig. 12). Cortex between
carnose and membranaceous, shell (figs. 1 3 , 14 ,
15, 16:) crustaceous, without valves, blackish,
having on each side below the apex two spots
(Jig. 15), on the back an areole resembling An
operculum (fig. 16);
Se ed (Jig. 17, 18 .) pendent (inversum, Rich.), ovate,
gibbous, whitish.1
Integument membranaceous.
Embryo of the same shape as the seed (fig. 19 .), white,
under a microscope longitudinally marked with
raised dots.
Cotyledon? (radicula, Rick, vitellus,Gcertn. (fig. 19 ,
20 . a. a.) large, ovate, fleshy, solid, a t the apex
obliquely truncated and grooved for the reception
of the plumule;
P lumule ? (cotyledon, Rich.) subulato-cylindraceouS
(fig- 1.9, 20. b. b.% obliquely placed and directed
towards the hilum of the seed.
Radicule ? (fig. 20. c.) a t the base of the plumule in a
4 | § ^lant of Ruppia maritima with its fructification in variouss mstaalgl etsu. beFrcilge.. 2. Young plant. Fig. S. Spadix
ot flowers seen from its anterior side; a. the ovaries. Fig. 4. The same seen from its posterior side; a. The
ovaries. Fig. 5. Anther. Fig. 6. The same burst open. Fig. 7. Grains o f pollen. Fig. 8. Spadix, after